#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"

#ifdef ENTROPY_OPT_SUPPORTED
#define FULL_COEF_BUFFER_SUPPORTED
#else
#ifdef C_MULTISCAN_FILES_SUPPORTED
#define FULL_COEF_BUFFER_SUPPORTED
#endif
#endif

typedef struct {
  struct jpeg_c_coef_controller pub; /* public fields */

  JDIMENSION iMCU_row_num;	/* iMCU row # within image */
  JDIMENSION mcu_ctr;		/* counts MCUs processed in current row */
  int MCU_vert_offset;		/* counts MCU rows within iMCU row */
  int MCU_rows_per_iMCU_row;	/* number of such rows needed */
  JBLOCKROW MCU_buffer[C_MAX_BLOCKS_IN_MCU];
  jvirt_barray_ptr whole_image[MAX_COMPONENTS];
} my_coef_controller;

typedef my_coef_controller * my_coef_ptr;

void start_iMCU_row( j_compress_ptr cinfo );

METHODDEF( wxjpeg_boolean ) compress_data JPP( ( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) );
#ifdef FULL_COEF_BUFFER_SUPPORTED
METHODDEF( wxjpeg_boolean ) compress_first_pass JPP( ( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) );
METHODDEF( wxjpeg_boolean ) compress_output JPP( ( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) );
#endif


void start_iMCU_row( j_compress_ptr cinfo ) {
  my_coef_ptr coef = ( my_coef_ptr ) cinfo->coef;
  if( cinfo->comps_in_scan > 1 ) {
    coef->MCU_rows_per_iMCU_row = 1;
  } else {
    if( coef->iMCU_row_num < ( cinfo->total_iMCU_rows - 1 ) )
    { coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->v_samp_factor; }
    else
    { coef->MCU_rows_per_iMCU_row = cinfo->cur_comp_info[0]->last_row_height; }
  }
  coef->mcu_ctr = 0;
  coef->MCU_vert_offset = 0;
}

METHODDEF( void ) start_pass_coef( j_compress_ptr cinfo, J_BUF_MODE pass_mode ) {
  my_coef_ptr coef = ( my_coef_ptr ) cinfo->coef;
  coef->iMCU_row_num = 0;
  start_iMCU_row( cinfo );
  switch( pass_mode ) {
    case JBUF_PASS_THRU:
      if( coef->whole_image[0] != NULL )
      { ERREXIT( cinfo, JERR_BAD_BUFFER_MODE ); }
      coef->pub.compress_data = compress_data;
      break;
      #ifdef FULL_COEF_BUFFER_SUPPORTED
    case JBUF_SAVE_AND_PASS:
      if( coef->whole_image[0] == NULL )
      { ERREXIT( cinfo, JERR_BAD_BUFFER_MODE ); }
      coef->pub.compress_data = compress_first_pass;
      break;
    case JBUF_CRANK_DEST:
      if( coef->whole_image[0] == NULL )
      { ERREXIT( cinfo, JERR_BAD_BUFFER_MODE ); }
      coef->pub.compress_data = compress_output;
      break;
      #endif
    default:
      ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
      break;
  }
}


METHODDEF( wxjpeg_boolean ) compress_data( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) {
  my_coef_ptr coef = ( my_coef_ptr ) cinfo->coef;
  JDIMENSION MCU_col_num;	/* index of current MCU within row */
  JDIMENSION last_MCU_col = cinfo->MCUs_per_row - 1;
  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
  int blkn, bi, ci, yindex, yoffset, blockcnt;
  JDIMENSION ypos, xpos;
  jpeg_component_info *compptr;
  /* Loop to write as much as one whole iMCU row */
  for( yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
       yoffset++ ) {
    for( MCU_col_num = coef->mcu_ctr; MCU_col_num <= last_MCU_col;
         MCU_col_num++ ) {
      blkn = 0;
      for( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
        compptr = cinfo->cur_comp_info[ci];
        blockcnt = ( MCU_col_num < last_MCU_col ) ? compptr->MCU_width
                   : compptr->last_col_width;
        xpos = MCU_col_num * compptr->MCU_sample_width;
        ypos = yoffset * DCTSIZE; /* ypos == (yoffset+yindex) * DCTSIZE */
        for( yindex = 0; yindex < compptr->MCU_height; yindex++ ) {
          if( coef->iMCU_row_num < last_iMCU_row ||
              yoffset + yindex < compptr->last_row_height ) {
            ( *cinfo->fdct->forward_DCT )( cinfo, compptr,
                                           input_buf[compptr->component_index],
                                           coef->MCU_buffer[blkn],
                                           ypos, xpos, ( JDIMENSION ) blockcnt );
            if( blockcnt < compptr->MCU_width ) {
              /* Create some dummy blocks at the right edge of the image. */
              jzero_far( ( void FAR * ) coef->MCU_buffer[blkn + blockcnt],
                         ( compptr->MCU_width - blockcnt ) * SIZEOF( JBLOCK ) );
              for( bi = blockcnt; bi < compptr->MCU_width; bi++ ) {
                coef->MCU_buffer[blkn + bi][0][0] = coef->MCU_buffer[blkn + bi - 1][0][0];
              }
            }
          } else {
            /* Create a row of dummy blocks at the bottom of the image. */
            jzero_far( ( void FAR * ) coef->MCU_buffer[blkn],
                       compptr->MCU_width * SIZEOF( JBLOCK ) );
            for( bi = 0; bi < compptr->MCU_width; bi++ ) {
              coef->MCU_buffer[blkn + bi][0][0] = coef->MCU_buffer[blkn - 1][0][0];
            }
          }
          blkn += compptr->MCU_width;
          ypos += DCTSIZE;
        }
      }
      /* Try to write the MCU.  In event of a suspension failure, we will
         re-DCT the MCU on restart (a bit inefficient, could be fixed...)
      */
      if( !( *cinfo->entropy->encode_mcu )( cinfo, coef->MCU_buffer ) ) {
        /* Suspension forced; update state counters and exit */
        coef->MCU_vert_offset = yoffset;
        coef->mcu_ctr = MCU_col_num;
        return FALSE;
      }
    }
    /* Completed an MCU row, but perhaps not an iMCU row */
    coef->mcu_ctr = 0;
  }
  /* Completed the iMCU row, advance counters for next one */
  coef->iMCU_row_num++;
  start_iMCU_row( cinfo );
  return TRUE;
}


#ifdef FULL_COEF_BUFFER_SUPPORTED


METHODDEF( wxjpeg_boolean ) compress_first_pass( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) {
  my_coef_ptr coef = ( my_coef_ptr ) cinfo->coef;
  JDIMENSION last_iMCU_row = cinfo->total_iMCU_rows - 1;
  JDIMENSION blocks_across, MCUs_across, MCUindex;
  int bi, ci, h_samp_factor, block_row, block_rows, ndummy;
  JCOEF lastDC;
  jpeg_component_info *compptr;
  JBLOCKARRAY buffer;
  JBLOCKROW thisblockrow, lastblockrow;
  for( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
       ci++, compptr++ ) {
    /* Align the virtual buffer for this component. */
    buffer = ( *cinfo->mem->access_virt_barray )
             ( ( j_common_ptr ) cinfo, coef->whole_image[ci],
               coef->iMCU_row_num * compptr->v_samp_factor,
               ( JDIMENSION ) compptr->v_samp_factor, TRUE );
    /* Count non-dummy DCT block rows in this iMCU row. */
    if( coef->iMCU_row_num < last_iMCU_row )
    { block_rows = compptr->v_samp_factor; }
    else {
      /* NB: can't use last_row_height here, since may not be set! */
      block_rows = ( int )( compptr->height_in_blocks % compptr->v_samp_factor );
      if( block_rows == 0 ) {
        block_rows = compptr->v_samp_factor;
      }
    }
    blocks_across = compptr->width_in_blocks;
    h_samp_factor = compptr->h_samp_factor;
    /* Count number of dummy blocks to be added at the right margin. */
    ndummy = ( int )( blocks_across % h_samp_factor );
    if( ndummy > 0 )
    { ndummy = h_samp_factor - ndummy; }
    /* Perform DCT for all non-dummy blocks in this iMCU row.  Each call
       on forward_DCT processes a complete horizontal row of DCT blocks.
    */
    for( block_row = 0; block_row < block_rows; block_row++ ) {
      thisblockrow = buffer[block_row];
      ( *cinfo->fdct->forward_DCT )( cinfo, compptr,
                                     input_buf[ci], thisblockrow,
                                     ( JDIMENSION )( block_row * DCTSIZE ),
                                     ( JDIMENSION ) 0, blocks_across );
      if( ndummy > 0 ) {
        /* Create dummy blocks at the right edge of the image. */
        thisblockrow += blocks_across; /* => first dummy block */
        jzero_far( ( void FAR * ) thisblockrow, ndummy * SIZEOF( JBLOCK ) );
        lastDC = thisblockrow[-1][0];
        for( bi = 0; bi < ndummy; bi++ ) {
          thisblockrow[bi][0] = lastDC;
        }
      }
    }
    if( coef->iMCU_row_num == last_iMCU_row ) {
      blocks_across += ndummy;	/* include lower right corner */
      MCUs_across = blocks_across / h_samp_factor;
      for( block_row = block_rows; block_row < compptr->v_samp_factor;
           block_row++ ) {
        thisblockrow = buffer[block_row];
        lastblockrow = buffer[block_row - 1];
        jzero_far( ( void FAR * ) thisblockrow,
                   ( size_t )( blocks_across * SIZEOF( JBLOCK ) ) );
        for( MCUindex = 0; MCUindex < MCUs_across; MCUindex++ ) {
          lastDC = lastblockrow[h_samp_factor - 1][0];
          for( bi = 0; bi < h_samp_factor; bi++ ) {
            thisblockrow[bi][0] = lastDC;
          }
          thisblockrow += h_samp_factor; /* advance to next MCU in row */
          lastblockrow += h_samp_factor;
        }
      }
    }
  }
  return compress_output( cinfo, input_buf );
}


METHODDEF( wxjpeg_boolean ) compress_output( j_compress_ptr cinfo, JSAMPIMAGE input_buf ) {
  my_coef_ptr coef = ( my_coef_ptr ) cinfo->coef;
  JDIMENSION MCU_col_num;	/* index of current MCU within row */
  int blkn, ci, xindex, yindex, yoffset;
  JDIMENSION start_col;
  JBLOCKARRAY buffer[MAX_COMPS_IN_SCAN];
  JBLOCKROW buffer_ptr;
  jpeg_component_info *compptr;
  for( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
    compptr = cinfo->cur_comp_info[ci];
    buffer[ci] = ( *cinfo->mem->access_virt_barray )
                 ( ( j_common_ptr ) cinfo, coef->whole_image[compptr->component_index],
                   coef->iMCU_row_num * compptr->v_samp_factor,
                   ( JDIMENSION ) compptr->v_samp_factor, FALSE );
  }
  /* Loop to process one whole iMCU row */
  for( yoffset = coef->MCU_vert_offset; yoffset < coef->MCU_rows_per_iMCU_row;
       yoffset++ ) {
    for( MCU_col_num = coef->mcu_ctr; MCU_col_num < cinfo->MCUs_per_row;
         MCU_col_num++ ) {
      /* Construct list of pointers to DCT blocks belonging to this MCU */
      blkn = 0;			/* index of current DCT block within MCU */
      for( ci = 0; ci < cinfo->comps_in_scan; ci++ ) {
        compptr = cinfo->cur_comp_info[ci];
        start_col = MCU_col_num * compptr->MCU_width;
        for( yindex = 0; yindex < compptr->MCU_height; yindex++ ) {
          buffer_ptr = buffer[ci][yindex + yoffset] + start_col;
          for( xindex = 0; xindex < compptr->MCU_width; xindex++ ) {
            coef->MCU_buffer[blkn++] = buffer_ptr++;
          }
        }
      }
      /* Try to write the MCU. */
      if( !( *cinfo->entropy->encode_mcu )( cinfo, coef->MCU_buffer ) ) {
        /* Suspension forced; update state counters and exit */
        coef->MCU_vert_offset = yoffset;
        coef->mcu_ctr = MCU_col_num;
        return FALSE;
      }
    }
    /* Completed an MCU row, but perhaps not an iMCU row */
    coef->mcu_ctr = 0;
  }
  /* Completed the iMCU row, advance counters for next one */
  coef->iMCU_row_num++;
  start_iMCU_row( cinfo );
  return TRUE;
}

#endif


void jinit_c_coef_controller( j_compress_ptr cinfo, wxjpeg_boolean need_full_buffer ) {
  my_coef_ptr coef;
  coef = ( my_coef_ptr )
         ( *cinfo->mem->alloc_small )( ( j_common_ptr ) cinfo, JPOOL_IMAGE,
                                       SIZEOF( my_coef_controller ) );
  cinfo->coef = ( struct jpeg_c_coef_controller * ) coef;
  coef->pub.start_pass = start_pass_coef;
  /* Create the coefficient buffer. */
  if( need_full_buffer ) {
    #ifdef FULL_COEF_BUFFER_SUPPORTED
    /* Allocate a full-image virtual array for each component, */
    /* padded to a multiple of samp_factor DCT blocks in each direction. */
    int ci;
    jpeg_component_info *compptr;
    for( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
         ci++, compptr++ ) {
      coef->whole_image[ci] = ( *cinfo->mem->request_virt_barray )
                              ( ( j_common_ptr ) cinfo, JPOOL_IMAGE, FALSE,
                                ( JDIMENSION ) jround_up( ( long ) compptr->width_in_blocks,
                                    ( long ) compptr->h_samp_factor ),
                                ( JDIMENSION ) jround_up( ( long ) compptr->height_in_blocks,
                                    ( long ) compptr->v_samp_factor ),
                                ( JDIMENSION ) compptr->v_samp_factor );
    }
    #else
    ERREXIT( cinfo, JERR_BAD_BUFFER_MODE );
    #endif
  } else {
    JBLOCKROW buffer;
    int i;
    buffer = ( JBLOCKROW )
             ( *cinfo->mem->alloc_large )( ( j_common_ptr ) cinfo, JPOOL_IMAGE,
                                           C_MAX_BLOCKS_IN_MCU * SIZEOF( JBLOCK ) );
    for( i = 0; i < C_MAX_BLOCKS_IN_MCU; i++ ) {
      coef->MCU_buffer[i] = buffer + i;
    }
    coef->whole_image[0] = NULL;
  }
}
